There is an emerging field for using systems, such as robotic systems, to assist medical personnel during a surgical procedure. These systems are configured so that a tool is maneuvered relative to an object of interest at a surgical site. The system typically includes a base with a plurality of linkages extending from the base. The system further includes a tool coupled to the plurality of linkages. The medical personnel may perform the surgical procedure with the system by providing instruction to the system to move the plurality of linkages and the tool with respect to the object.
Often a navigation system is employed to assist in accurately moving the tool to desired positions relative to the object. Navigation systems provide accurate position and orientation information for the tool and other objects being tracked, especially when these objects move within a relatively large working volume. The navigation-based position and orientation information is often provided to at least partially influence movement and positioning of the linkages of the system relative to a patient's anatomy of interest.
Additionally, movement of the tool can be controlled in an open loop fashion using position and orientation information derived from a plurality of encoders associated with the plurality of linkages. When utilized for relatively small movements, such encoders can provide more precision than the navigation system in a localized area of interest. As such, encoder-based position and orientation information may be useful when there is a desire to operate at a faster rate outside of the closed loop control of the navigation system. Thus, there are different benefits to using the navigation system and/or the encoders for generating movement commands.
Conventional systems face challenges with managing the navigation-based and encoder-based information. Mainly, the linkages exhibit a response frequency that is slower than the frequency at which the navigation-based position and orientation information is provided. More specifically, the linkages, motors, joints, etc. of most systems have some flexibility or play. This flexibility limits the reaction time between movement commands and ultimate movement and settling of the tool. If the position and orientation information from the navigation system is utilized for generating movement commands at a frequency faster than the tool is able to move and settle in reaction to such movement commands, the closed loop control of the system will become unstable. Additionally, the slow response frequency of the linkages inhibits the frequency at which this navigation-based position and orientation information can be utilized to influence positioning of the tool. Moreover, conventional systems do not allow for dynamic adjustment of the aforementioned frequencies. Thus, the versatility and stability of conventional systems is limited for various applications and situations.
Accordingly, there is a need in the art for systems and methods for solving the aforementioned problems.